Murder Sheet — A Talk with ISP Forensic Genealogist Bradley Marchant, Part One: How To Be A Silent Witness

Date: March 31, 2026 | Host(s): Áine Cain & Kevin Greenlee | Guest: Bradley Marchant, Indiana State Police Forensic Genealogist

Episode Overview

This episode features an in-depth interview with Bradley Marchant, a forensic genealogist with the Indiana State Police’s new Forensic Investigative Genetic Genealogy (FIG) unit. Marchant discusses his personal journey into genealogy and genetic genealogy, demystifies how DNA and genealogical research help solve cold cases, and outlines how everyday listeners can contribute to law enforcement efforts as "silent witnesses" by sharing their DNA profiles.

1. Bradley Marchant’s Introduction and Background (02:42–06:29)

• Getting Started in Genealogy:
  • Began as a teenager after discovering old photographs at a flea market, leading to a lifelong passion for genealogy.
  • Formalized his training with a degree in family history genealogy from Brigham Young University.
  • Worked at Ancestry.com, appeared on genealogy TV shows, and participated in research projects.
  • Transitioned into genetic genealogy about 10–11 years ago after self-testing and discovering unexpected African and Portuguese heritage due to a previously unknown biological ancestor in his family.
  • Notable moment:
    • “My mother learned she’s 25% Portuguese from the island of the Azores... she never really understood where that came from.” (05:45—06:15)
  • Emphasized how DNA testing often reveals family secrets, noting that 10-15% of test-takers discover “something shocking.”
  • Coined genealogy’s old joke: "Mommy’s baby, daddy’s maybe."

2. Explaining Genetic Genealogy and Its Role in Law Enforcement (12:15–19:55)

• Technical Foundations:
  • Two-Step Process:
    1. Case selection: Must be a violent crime, usually cold (e.g., murder, sexual assault), and all standard DNA searches (CODIS database) must be exhausted.
    2. DNA reprocessing: STR profiles (law enforcement) differ from SNP profiles (used in genealogy companies like AncestryDNA, 23andMe).
  • CODIS vs. FIG:
    • CODIS uses STR profiles for identifying close family matches or evidence from crime scenes.
    • FIG relies on broader SNP profiles to establish distance relationships with living individuals who have participated in consumer DNA testing.
  • Law Enforcement Databases:
    • Major public databases: GEDmatch and FamilyTreeDNA (both requiring opt-in for law enforcement searches).
    • Listener takeaway: Anyone can upload their DNA (from any consumer kit) to GEDmatch and opt-in, potentially helping to solve crimes or identify missing persons.
  • Notable quote:
    • “100% anybody can do that. We call it being a silent witness.” — Bradley Marchant (24:06)

3. How Investigative Genetic Genealogy Works — The Process (24:06–37:35)

• Step-by-Step Scenario:

  • Once DNA is uploaded to a searchable database, investigators receive a list of DNA matches, ranked by degree of relationship (e.g., second or third cousins).
  • Researchers map out family trees for every DNA match, tracing shared ancestry and identifying overlap points.
  • As in example: For a 1975 Jane Doe, if two second cousins are DNA matches, the team finds their common great-grandparents, then traces descendants for potential candidates matching the Doe's demographic data.
  • When closer DNA matches exist (second or third cousins), leads develop more quickly; more distant matches require building trees back to fifth/sixth great-grandparents, which can involve mapping hundreds of individuals.
  • Case complexity increases with factors like international ancestry, adoptions, or incomplete family histories.
  • The more people in public databases, the easier (and faster) cases are solved.

• Memorable analogy:

  • “It’s kind of like a spider web of who’s related to who.” — Bradley Marchant (24:32)

4. Timelines, Challenges, and “Silent Witnesses” (30:57–38:11)

• Typical Timelines:

  • Fastest case: “Solved” within 5–6 days thanks to a close DNA match.
  • Average case: 2–4 weeks, often working multiple cases in parallel.
  • Difficulties arise when closest matches are distant (e.g., fourth/fifth cousins) or adoptees.
  • Historical factors (e.g., African American ancestry with fewer records), regional differences, and adoption events can slow investigations.

• Importance of Public Participation:

  • The more people who upload DNA and opt-in, the greater the chance of finding closer matches and solving cases quickly.
  • Encouragement to listeners: “If you want to be involved, upload... talk to your relatives, upload their DNA kits... your parents might be a closer match than you would be...” (35:47)

• Silent Witness Concept:

  • Emphasizes that most contributors are never contacted or made public; their DNA sits quietly in the background, potentially unlocking decades-old mysteries.

5. Record Research and Building Family Trees (41:47–45:21)

• Records and Tools Used:

  • No secret or privileged repositories—Marchant and the team rely on the same records and online tools as hobbyist genealogists: census records, vital records, newspapers.com, FindAGrave, Ancestry.com, and more.
  • For international cases, local resources (e.g., Catholic church records in Latin America, German church archives) may be necessary.
  • Occasionally, rare in-person research at libraries if needed.

• Memorable moment:

  • “We don’t have a secret database of everybody’s DNA hidden somewhere. And we don’t have a secret database of extra records...” — Bradley Marchant (42:40)

6. Bradley’s Path to ISP Forensic Genealogy and Guarding Privacy (45:21–53:11)

• Career Opportunity:

  • After working for Ancestry.com and a stint teaching, he discovered the Indiana State Police was seeking a genealogist.
  • Became the first specifically-hired genealogy investigator for the Indiana State Police, now working as part of a small growing team.
  • “Indiana is one of the first states to decide to do it in house.” (14:13)

• Confidentiality and Public Reassurance:

  • Privacy is paramount: The genetic information and family trees built for investigations are not made public.
  • Only in rare cases—if absolutely necessary—does law enforcement contact a DNA match to request more info.
  • “We want our listeners to know that your family tree and your personal information is all kept very private so it is not available to the public.” (49:59)

• Being a "Confidential Informant":

  • The public, by sharing DNA, becomes a “silent witness” or “confidential informant” — never named in court or in news reports.
  • Even if your DNA is a pivotal match leading to the identification of a victim or perpetrator, you remain uncontacted and anonymous unless direct follow-up is instrumentally required.

7. Final Thoughts: The Impact of Genealogy in Law Enforcement (53:11–53:57)

• Broad Impact and Notable Cases:

  • Highlighted recent successes, including identification of both unknown homicide victims and perpetrators (e.g., Herb Baumeister case).
  • Some cases date back over a century, including identities established from Civil War-era remains.

• Listener Takeaway:

  • Anyone can meaningfully contribute to solving crimes and providing closure for families by uploading their genetic profile and opting in for law-enforcement use.
  • Confidentiality, voluntary participation, and privacy protections underscore the ethical use of this technology.

Notable Quotes & Moments

• On Discovering Family Secrets:
  • “It’s estimated about 10–15% of people who take a DNA test find something shocking.” (06:15)
• On Being a Silent Witness:
  • “I love knowing that potentially my DNA could help solve a crime... how cool would it be if you knew that your DNA was the thing that helped solve a serial killer?” (24:15)
• On the Reality of the Work:
  • “So sometimes we have to kind of abandon looking for a particular tree and move on to another DNA match... But we don’t necessarily always work on one case from start to finish before going to the next case.” (32:50)
• On Privacy Concerns:
  • "Your DNA is essentially the informant part, your DNA is essentially providing clues to help us learn who this person is. Because of that, your information is kept completely private." (52:07)
• On Tools Used:
  • “We use the same Ancestry.com and FamilySearch and Find a Grave and newspapers that anybody can use.” (42:33)
• On Case Volume:
  • “One of my cases, I think it got up to 3,000 people that I had to piece together in this massive network of family trees. My most recent case that was a solve... under 400 people." (53:16)

Key Timestamps for Important Segments

• Bradley’s Introduction & Personal Journey: 02:42–06:29
• Explanation of Genetic Genealogy in Law Enforcement: 12:15–19:55, 18:17–19:55 (CODIS & SNP profiles)
• How Listeners Can Help (“Silent Witness”): 23:59–24:32, 35:47–37:35
• Step-by-Step Case Scenarios & Timeframes: 24:06–33:38
• Genealogy Tools & Public Databases (No Secret Data): 41:47–45:21
• Privacy, Confidentiality, and Reassurance: 49:40–53:11

Conclusion

This episode offers a rare, candid look inside the world of forensic investigative genetic genealogy, balancing technical details with accessible explanations. Bradley Marchant’s insights demystify the role of DNA in solving cold cases and stress the immense value of public participation—reassuring listeners about privacy, ethics, and the real-world impact of being a "silent witness." The conversation humanizes both the science and those working behind the scenes, making this an essential listen for true crime and genealogy enthusiasts alike.

Stay tuned for Part Two, where the discussion continues.